This invention relates generally to doors for motor vehicles, and relates more particularly to a hybrid composite reinforced door inner panel.
Conventional doors for motor vehicles generally have been constructed on an element by element basis requiring a sequence of operations during an assembly line process. The main door unit usually comprises a thin metal stamping forming an inner panel, while an outer panel is hemmed around the marginal edges of the inner panel. The automotive industry is continually trying to design lightweight door structures that provide high volume economic production together with good stiffness-to-weight ratios. For example, U.S. Pat. No. 5,581,947 teaches a lightweight vehicle door including, in one form, outer and inner plastic panels bonded together with the inner panel molded with upright forward, aft and intermediate frame portions. Motor vehicle doors have also been constructed with resin transfer molded inner or outer panels, with large steel panels on the hinge pillar and latch pillar for strength and stiffness. Other doors have used sheet molding compound and smaller steel reinforcements.
The present invention is a door panel for a motor vehicle. The door panel comprises a front portion and a rear portion connected to the front portion. The front portion comprises carbon fiber sheet molding compound, and the rear portion comprises sheet molding compound containing glass fibers.
Accordingly, it is an object of the present invention to provide a door panel of the type described above that reduces door sag.
Another object of the present invention is to provide a door panel of the type described above that reduces permanent deflection.
Still another object of the present invention is to provide a door panel of the type described above that eliminates any need for extensive hinge pillar reinforcement.
Still another object of the present invention is to provide a door panel of the type described above that weighs less than conventional door panels.
These and other features and advantages of the invention will become further apparent from the following detailed description of the presently preferred embodiments, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the invention rather than limiting, the scope of the invention being defined by the appended claims and equivalents thereof.